Valve.



P. W. KNAU?.

VALVE.

APPLICATION FILED SEPT. 21, 1907.

Patented NW2, 1909.

IIYENTQRI PAUL W. KNAUF, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TOSCI-IUTTE .AND KOERTING COMPANY, OP PHILADELPHIA, PENNSYLVANIA, ACORPORATION OF PENNSYLVANIA.

VALVE.

Specication of Letters Patent.

Patented Nov. 2, 1909.

To all whom it may concern:

Be it known that I, PAUL WV. KNAUF, a citizen of the United States ofAmerica, residing in the city and county of Philadelphia, in the Stateof Pennsylvania, have invented a certain new and useful Improve ment inValves, of which the following is a true and exact description,reference being had to the accompanying drawings, which form a partthereof.

The present invention relates to valves for the control of fluid such assteam and water, and particularly to that type of valve in which onaccount of its size or for other reasons the main valve is provided witha pilot valve controlled passage extending through it by which the inletand outlet sides of the valve casing may be connected while the mainvalve is on its seat, thus facilitating the operation of the valve. Invalve constructions of this kind it is desirable that in opening, thepilot valve should open fully before the main valve moves off its seat,and that in closing, the main valve should be seated before the pilotvalve is seated. Furthermore, the pilot and main valves should be socontrolled that neither is permitted to hammer on its seat by reasons ofvariations in the pressure or flow of the fluid controlled, at the sametime each valve should preferably be so connected to the. operatingmeans that it can seat itself properly.

The object of the present invention is the provision of simple andeffective connections between the main and pilot valves and a singleoperating device or stem by which the main and pilot valves are bothoperated in the desirable manner above described.

The various features of novelty which characterize my invention arepointed out with particularity in the claims annexed to and forming apart of this specification. For a better understanding of my invention,however, reference may be had to the accompanying drawings anddescriptive matter in which I have illustrated and described forms inwhich my invention may be embodied.

In the drawings, Figure l is a sectional elevation taken on the line 1-1of Fig. 2. Fig. 2 is a sectional elevation taken on the line 2-2 of Fig.l.

In the drawings, referring first to the construction shown in Figs. land 2, A represents the valve casing provided with inlet chamber A andoutlet chamber A2, these chambers being separated by the diaphragm A3having in it the valve seated port A4. Preferably, a removable valveseat member A5 is employed as shown. The valve casing bonnet B isdetachably secured to the valve casing. In the form shown, the bonnet isprovided with a cylinder B', which extends into the inlet chamber, andthe main Valve C, which seats on the valve seat member A5 and controlsthe port A, is provided with a hollow piston extension C which isreceived in the cylinder B. The interiors of the cylinder B and of thehollow piston C have restricted communication with the inlet chamber ofthe valve casing proper through the port C2 of the hollow piston andport B2 in the wall of the cylinder B. The valve C has a pilot valveseated port C3 which leads through the valve and connects the outletpassage A2 with the interior of the hollow piston C. The port C3 iscontrolled by the pilot valve D adapted to seat itself on the seat C4formed on the main valve C.

The stein E, by which the main and pilot valves are operated, passesthrough a suitable st-uffing box Bt formed in the cover member B3 whichcloses the upper end of the bonnet B. The upper end of the valve sternE, in the form shown in Figs. l and 2, is threaded, the threaded portionE passing through a nut E2 secured in the yoke B5 carried by the covermember. The lower end of the valve stem has a collar E3 which isswiveled in the hollow upper end of the .pilot valve D, the pilot valveand stem being connected together by the externally threaded collar Dscrewed into the upper end of the hollow portion of the valve D. rlhebody of the pilot valve D is guided by a collar or boss C2 carried bythe main valve. A plate C, detachably connected to the upper end of theboss C5 by the bolt C7, may be arranged to engage the collar D and limitthe movement of the pilot valve D away from its seat Ct.

Two or more arms F are pivotally connected to the main valve as by meansof pintles F journaled in ears carried by the plate CG. The arms orlinks F are pivotally connected at F2 to arms or links G, which in turnare pivotally connected at Gr to a colfg sanfterA lar or crosshead Ilswiveled on the stem E and held against axial movement thereon by theupper and lower collars H and H2. The arms F have extensions F 3. Wvhenthe main valve is seated and the arms F and G buckle as the pilot valveis moved toward or away from its seat, the extensions F3 engage thecasing guide surface BG. Then the main and pilot valves are both offtheir Y seats, the extensions F3 engage the casing guide surface B7. Thecasing guide surface BT is cylindrical and forms the inner wall of thebody of the bonnet B, and the guide surface BG is in the form of a zonebeneath the lower end of the cylindrical surface BT.

In operation, assuming the valve to be closed, the pilot valve is firstopened by moving the valve stem E upward. This, of course, may be doneby the nut and screw arrangement as shown or by any other of the wellknown means employed for moving valve stems. Until the pilot valve isentirely open the main valve is anchored on its seat by the arms F whichform struts extending between the curved surface B6 of the bonnet B andthe main valve. The parts are so proportioned that when the upwardmovement of the stem is continued until the pilot valve engages theplate C, when of course the main valve must move up with the pilotvalve, the extensions F3 are moved out of engagement with the casingguide surface B, and into position to engage the casing guide surfaceB7, and on further upwarlL movement of the stem the parts F 3 engage theguide surface B7. F3 engage the casing guide surface B7, buckling of thearms or links F and G is of course prevented and the valves D and C aremain.- tained at their maximum distance apart. In closing, the reverseoperations occur, the pilot valve beginning its relative movement ofapproach toward its seat C4 only after the main valve has seated itself.In Fig. l t-he left hand arms F and G are shown in dotted lines in theposition corresponding to the closed position of the main valve and thewide open position of the pilot valve.

IV ith the construction described, it willl be observed that both thepilot and main valves are movably connected to the stem so that each isfree to rotate independently of the stem and the other valve, ifnecessary, to permit the valve to seat itself properly, while at thesame time they valves are not positively rotated on their seats inopening or closing. IVhile the main valve is off its seat, the arms Fand G form means positively holding the two valves apart, but during theopening or closingy movement of the pilot valve the main valvek is ineffect disconnected from the pilot valve, and is positively anchoredagainst its seat by the IVhile the extensions arms F extending betweenitV and the casing guide surface BG.

It will be understood that when the main valve is on its seat and thepilot valve is olf its seat the interiors of the cylinder B and hollowpiston C are in communication with the outlet side of the valve casing,and, as the flow of fluid into the cylinder and hollow piston throughthe passages C2 and B2 is restricted, the main valve C becomespractically balanced, where the piston C is of substantially the samecross sectional area as the body of the main valve. At all timeshammering of either valve on its seat is prevented by the connectionsdescribed.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent is l'. In combination, a valve casing having avalve seated port, a main valve for said port having a passage extendingthrough it, a pilot valve controlling the passage through the mainvalve, a stem to which the pilot valve is directly connected, a collarcarried by the stem and free to rotate thereon but held againstlongitudinal movement with respect thereto, hinged links connecting thesaid collar andr main valve, said valve casing being provided with acylindrical curved guide surface, arranged to engage said links and holdthem against buckling when the main valve is off its seat, and with azonoidal guide surface engaging said links to thereby hold the mainvalve on its seat except when the pilot valve is wide open.

2. In combination, a valve casing having a valve seated port, a mainvalve for said port having a passage extending through it, a pilot valvecontrolling the passage through the main valve, a stem connected to thepilot valve, a collar carried by the stem and free to rotate thereon,but held against' longitudinal movement with respect thereto, armspivoted to the main valve, and other arms pivoted to the first mentionedarms and to said collar, said casing having a Zonoidal curved guidesurface, and the arms connected to the main valve having a surface whichengages said Zonoidal surface when the main valve is seated and when thearms buckle as the pilot valve in closing or opening its port approachesor recedes from the main valve, whereby the main valve is anchoredagainst movement off its seat except when the pilot valve is wide open,said casing having other cylindrical guide surface engaging said arms tohold `them against buckling when the main valve is moved ofi' its seat.

PAUL W. KNAUF. fitnesses ARNOLD KATZ, D. STEWART.

